The subject matter disclosed herein relates generally to microfluidic systems, and more particularly, to systems and methods for metering a reagent.
Various medical procedures utilize reagents or mixtures of reagents for treatment or diagnosis of patient conditions. For example, certain imaging modalities use radiopharmaceuticals to generate medical images of a patient. Examples of such imaging modalities include positron emission tomography (PET) and single photon emission computed tomography (SPECT). PET and SPECT are used in conjunction with a radiopharmaceutical or a radioactive tracer that is administered to (e.g., injected into) the patient, which results in the emission of gamma rays from locations within the patient's body. The emitted gamma rays are then detected by the PET or SPECT detector and an image is created based on characteristics of the detected gamma ray emissions. Additionally, certain radiopharmaceuticals may be used to treat various patient conditions. Examples of radiopharmaceuticals include FDG (2-[18F]-fluoro-2-deoxyglucose), other 18F based fluorinated tracers, 13N ammonia, 11C based tracers, 15O gas, and 15O water, and others.
Radiopharmaceuticals have short half lives ranging from about two minutes to about 2 hours, and thus, the injection and imaging generally takes place within a short time after production of the radiopharmaceutical. Accordingly, to prevent undue decay of such radiopharmaceuticals prior to use, the radiopharmaceuticals are often synthesized onsite at medical facilities where the PET or SPECT system is located. However, the systems used to generate such radiopharmaceuticals often use dedicated pumps for each reagent used in the synthesis process. The dedicated pumps may have limited volumes, and therefore limit scaling up or scaling down the amount of reagents used in the system. Moreover, the pumps may need to be cleaned after each use to minimize contamination of subsequent batches of radiopharmaceuticals. Decontamination of the pumps may be inefficient, generate additional waste, and reduce technician workflow. Accordingly, there is a need to develop a system to overcome the limitations associated with the use of dedicated pumps to generate radiopharmaceuticals.